1. Field of the Invention
The present invention relates to an accelerator, particularly to an accelerator supporting virtual machine migration and its method for realizing the virtual machine migration.
2. Description of the Related Art
Cloud computing is a new Internet-based computing manner, and provides on-demand computing for individual and enterprise users through heterogeneous and autonomic services on the Internet. Cloud computing is usually considered to include the following levels of services: Infrastructure as a Service (IaaS), Platform as a service (PaaS) and Software as a Service (SaaS). The virtualization technology is an important and fundamental technology in “cloud computing” technology, and since it has the capabilities of on-demand configuration and dynamic migration, it becomes a key for realizing dynamic and scalable extension of cloud computing. In order to realize the high flexibility of the cloud computing to satisfy policies and requirements of services or management, dynamic migration and aggregation of virtual machines among physical machines need to be performed frequently, so as to achieve the objectives of reducing energy consumption, improving resource utilization and lowering management costs, etc.
However, virtual machine migration is a high I/O sensitive process. During the process where the virtual machine is migrated, since the services or applications thereon are still in operation, this will produce unexpected influence on the migration of the virtual machine. And, currently virtual machines usually perform service-related logic operations and IO operations using the accelerator on the physical machine, in which case, the problem becomes more severe and challenging, since only after the accelerator has processed the current task request in the task queue can the virtual machine be migrated; while the time for the accelerator to finish processing the request is uncertain, making the time for the virtual machine to be migrated become more uncertain. And, a long time of wait makes new requests of the user unable to be processed, which greatly reduces quality of services for the user.
Therefore, in the case that the physical machine provides an accelerator application and support, how to improve the efficiency and performance of the virtual machine migration is of vital importance and value to realizing the elasticity of the cloud system and ensuring the quality of the cloud service.